Centrifugal separator



Feb. 9, 1932. H. w. FAWCETT 1,344,917

CENTRIFUGAL SEPARATOR Filed May 9. 1931' 2 Sheets-Sheet l JNVEN TOR Feb. 9, 1932.- H. w. FAWCETT CENTRIFUGAL SEPARATOR Filed May 9, 1931 2 Sheets-Sheet 2 :INVFNTOH Patented Feb. 9, 1932 UNITED STATES PATENT OFFICE min-0L1) WILLIAM FAWCETT, or HARROGAIE, ENGLAND CENTRIFUGAL SEIAR-ATOR Application filed May 9, 1931, Serial No. 536,296, and'in Great Britain February 27, 1930.

This invention relates to improvements in and relating to centrifugal separators and more particularly to means for varying the cross-sectional area of nozzles, apertures, conduits or the like, through which a constituent or constituents separated in the interior of the machine is or are adapted to'be discharged.

The invention aims at avoiding the choking of such nozzles, apertures, conduits or the like, due for example to solid particles jamming therein.

To this end, according to the invention there are provided on or in connection with said-discharge nozzles, apertures, conduits or the like, means adapted to be operated by variations in the flow of the constituent issuing. through said discharge nozzles or the like, for automatically altering the cross-sectional area thereof, so as to permit of the discharge of matter which would normally tend-to choke up said nozzles or the like.

The inventionv also contemplates the employment as the means adapted toalter the crosssection of the discharge nozzles or the like, of a slide valve, preferably suspended from the nozzle or the like by links.

- 1 Further objects and advantages of the invention will become apparent as the description thereof proceeds. i

. In the accompanying drawings Fig. 1 is a partial transverse section of a centrifuge casing showing one variable discharge aperture in accordance with the'inven tion- Fig. 2 is a similar view of a second embodiment; Y

Fig. 3 is a partial transverse section of still a further embodiment of centrifuge casing showing one variable discharge aperture in accordance with the invention; and

Figs. 4 and 5 are partial radial and transverse sections respectively of a fourth embodiment of a centrifuge casing showing one variable discharge aperture in accordance with the invention. l y

In the drawings,like parts are denoted by like characters of referencep In the embodiment illustrated in Fig. 1,

1 denotes the drum wall of the centrifugal separator, 2 a valve member of conical shape adapted to move in a peripheral discharge aperture 3, in the casing'l. Said valve mem her 2 is screwed on to a spindle 4 carryingthe stop 5 adapted to abut against the outer. pe riphery of the casing 1 to limit the inner travel of the spindle 4 and valve member 2. Pivotally secured to the spindle 4 at 6 is a spider 7 carrying a tray or the like vessel 8 provided with a centralaperture 9. In the o0 embodiment illustrated in Fig. 1, the vessel 8 is comparatively shallow and the aperture 9 is of insufficient size to allow all the sludge or liquid to escape when the separator is functioning normally,.so that part of said liquid (55. overflows around the edges of the vessel 8. 1O denotes a lever bearing against the outer side of the pivot .6 and fulcrumed on a pivot 11 formed in a bracket 12 or lug mountedon the outside of the casing .1. The other end of said lever'lO carries a weight 13. Inorder to limit the inward movement of the weight '13 and thus the outward movement-of the cup 8 and valve member 2 underthe action of centrifugal force,'the weight 13 carries an adjustable screw 14.

The apparatus functions in the following manner :WVhen the separator is set into rotation, but is still empty the spindle 4 and member 2are retract-ed to their maximum 20 extent into the interior of the casing 1 by the centrifugal force exerted on the weight 13 but are prevented by the stop 5 from being drawn out of the aperture 3.

On the separator being filled with liquid 8:. and functioning normally, the head of sludge or liquid escaping into the tray 8 and filling same .forces the tray outwardly thereby drawing the valve member 2 through the nozzle 3 counter to the force of the weight 13. no In the event of the remaining free cross-section of the aperture 3 becoming choked by an obstruction, the supply of sludge or liquid to the tray 8 will decrease and the tray will thus empty through theopening 9 with the result that the centrifugal force exerted on the tray 8 will be reduced so that the weight 13. will move outwardly and thus the valve member 2. inwardly, thereby exposing a greater cross-sectional areaof the nozzle 3 1 30 so as to permit the obstruction to be flushed away. The tray 8 then again receives a supply of sludge or liquid and the arrangement resumes its normal position.

The embodiment illustrated in Fig. 2 differs from that described with reference to Fi 1, in the following respects go) The valve member 2, instead of being conical consists of a cylindrical member having a flat 2a formed therein.

(b) The lever 10 is a bell crank lever consistin of the portions 10a, 10?). This offers the advantage of rendering the action of the valve member abrupt since through the bell crank lever an increasing retracting leverage is applied to the valve member as it is retracted towards the interior of the separator.

(c) The cup 8 instead of being a shallow tray is deeper and the aperture 9 is so dimensioned that the contents do not spill over the side of the cup but maintain a certain level in the cup. Thus the cup in normal operation is only partially filled with sludge or liquid and moves outward under the action of centrifugal force immediately the normal level is exceeded and conversely, inwards when the normal level decreases. This arrangement is more sensitive than that described with reference to Fig. 1 and responds more readily, in fact, even to incipient choking of the nozzle 3.

n the embodiment shown in Fig. 3, the valve 2 is of the slide valve type and is pivotally mounted by links 21), on a nozzle screwed. into the drum wall 1. The slide valve'2 is so arranged as to leave a permanent small opening through which sludge constantly issues. This issuing sludge is deflected by a deflecting plate 16 which is so constructed and arranged as to guide the sludge into the cup 8 (which in this embodimerit ismounted out of line with the nozzle '15) through the opening 9 in the bottom thereof. The cup 8 is mounted on a lever 10,

.- which is counterweighted at 13 and fulurumed on the spindle 11. Fast with the links 26 is a bell crank 17 adapted to be engaged by the-lever 10 when'the same moves outwards. Said bell crank 17 is provided at =its'other end with a weight 18 which tends to oppose the opening of the valve 2.

This embodiment operates as follows:

When the separator is rotating at the commencement of the purifying operation with the separator empty the valve 2 is fully open. On liquid to be purified being fed into the separator, sludge issues continuously through the discharge aperture and is deflected into the cup 8 which, being empty. is init-s innermost position. The cup 8 gradually fills and when it has filled to a sufiicient extent to overcome the balancing force of the weight 13, moves outwards thereby closing'the valve 2 except for the small per nmnent leak hole 20 through which sufficient sludge issues to maintain the desired sludge level in the cup 8. If the leak hole 20 should be obstructed by accumulated sludge the supply of sludge to the cup 8 will cease and the cup will drain and move inwardly thereby opening the valve 2 and permitting the discharge of the obstructing sludge.

In the embodiment illustrated in Figs. 4 and 5, the leaking cup 8 of Figs. 1 to 3 is replaced by a rotating vane or bucket wheel 20 mounted at one end of the counterweighted lever 10. Said wheel 20 is positively driven at a relatively slow rate by reduction gearing comprising a stationary worm collar 21 fixed to the framework of the machine around the spindle, worm wheel 22 fast with worm 23 engaging a worm wheel 24 mounted on a shaft 25 carrying at its other end a gear 'wheel 26 drivinga toothed 'ring 27 which in turn drives the wheel 20 through gear-train 28, 29. The ring-27 is mounted on the drum casing 1 by ball bearings 30. The lever 10 carries a rod 10a adapted to engage a rod 2d fast with and transverse to the links 2?).

This apparatus operates as follows:

The wheel 20 constantly revolves ata slow speed in front of the discharge nozzle 15 and in normal operation it is kept in its'outermost position by the small streamiof slud issuing through the permanent leak holes 20 and filling each successive compartment of the wheel which spills its contentsduring'its rotation.

If the permanent leak hole 20 should become choked, the supply of sludge to the wheel 20 will cease and the wheel will empty and move nearer the nozzle 15, whilst however still be positively driven by virtue of the provision of a suitable clearance between the teeth of gear Wheels 28 and 29. During the inward movement of the lever 10 the rod 10a will strike against the transverse rod 2d and thereby cause the opening ofrthe valve 2 with the consequent discharge of'the obstructing sludge. The wheel 20 will thenagain move outwards and the valve 2 will close under the influence of centrifugal force.

It should be well understood that the herein-described embodiments are given solely by way of example and that I do not wish to limit myself thereto but that I desire to cover by my Letters Patent all such constructions and modifications as fall within the scope of the appended claims.

I claim 1. In a centrifugal separator. a casing, a plurality of permanently open discharge apertures for dense constituent in said casing, means individual to each of said discharge apertures for alteringthe cross section thereof duringthe operation ofthe separator and means subject to centrifugal force and individual to and co-rotating with each discharge aperture, which are influenced centrifugally by variations in the flow of dense constituent through said discharge aperture and act on said cross section altering means.

2. In a centrifugal separator, a permanently open discharge. aperture for dense constituent, a valve cooperating with said discharge aperture, a receptacle for dense constituent arranged in front of said dischargeaperture and a counterw'eighted lever in operative connection with said receptacle and with said valve in such a manner that the position of the valve with respect to the aperture is regulated by the amount of material in said receptacle, all of said parts being carried by and moving with the separator.

3. In a centrifugal separator, a permanently open discharge aperture for dense constituent, a slide valve movable in front of said discharge aperture, a receptacle for dense constituent arranged in front of said discharge aperture and a counterweighted lever in operative connection with said sludge receptacle and with said valve in such a manner that the position of the valve with respect to the aperture is regulated by the amount of niaterial in said receptacle, all of said parts being carried by and moving with the separator.

4. In a centrifugal separator, a permanently open discharge aperture for dense constituent, a slide valve movable in front of said discharge aperture, an ap'ertured receptacle for dense constituent arranged in front of said discharge aperture, a counterweighted lever carrying said apertured receptacle and in operative connection with said valve and deflecting means in front of said discharge aperture to deflect issuing dense constituent against the aperture in said receptacle in such a manner that the position of the valve with respect to the aperture is regulated by the amount of material in said receptacle, all of said parts being carried by and moving with the separator.

5. In a centrifugal separator, a permanently open discharge aperture for dense constituent, a valve co-operating with said discharge aperture, a rotary receptacle for dense constituent arranged in front of said discharge aperture and a counterweighted lever carrying said rotary receptacle and operatively connected with said valve in such a manner that the position of the valve with respect to the aperture is regulated by the amount of materialjin said receptacle, all of said parts being carried by and moving with the separator. V

6. In a centrifugal separator, a permanently open discharge aperture for dense constituent, a valve co-operating with said discharge aperture, a rotary receptacle arranged to receive a constituent issuing from the separator and mounted on a counterweighted lever in operative connection with said valve and driving means for said rotary receptacle in such a manner that the position of the valve with respect to the aperture is regulated by the amount of material in said receptacle, all of said parts being carried by and moving with the separator.

7. In a centrifugal separator a permanently open discharge aperture for dense constituent, a valve co-operating with said discharge aperture, a receptacle arranged to receive dense constituent issuing from said discharge aperture and means constraining said receptacle towards the axis of the separator and counter to the constraint exercised by the dense constituent in said receptacle, said constraining means being operatively connected to said valve in such a manner that the position of the valve with respect to the aperture is regulated by the amount of material in said receptacle, all of said parts being carried by and moving with the separator.

In testimony whereof, I aiiix my signature.

I HAROLD WILLIAM FAIVGETT. 

